A turf aerator (11) provided with a reciprocating drive mechanism (33, 37) torepeatedly drive a leg (35) carrying a tine (31) vertically into the ground (52)and retract it again at regularly spaced intervals, the tine leg (35) being substantiallyrigid and pivotally mounted at its upper end (36) to a drive assembly (33). Thetine leg (35) is provided with a cam surface (160) in the forward direction anda forward guide arrangement (141) including a forward travel limiting stop,acting on the cam (160), to limit forward travel of the tine leg (35) and therebymaintain a substantially vertical travel path for the leg (35).
